Lucy, the latest from renowned French writer/director Luc Besson, might just be his most ambitious work in the action genre yet. Much more akin to The Fifth Element than it is to La Femme Nikita and Leon: The Professional in terms of Besson’s previous action efforts, it’s nothing less than a filmmaker’s exploration of what it might be like for a human being to fulfill his or her full potential, what that journey might be like. It’s as much high-concept as it is high-octane, and while some audiences might get lost in all the theoretical and metaphysical speculation Besson builds into his story, it’s tough to not appreciate the way he tells that story visually. In short, he makes sure that it’s a wild and fascinating ride to omnipotence, one that viewers aren’t likely to forget.

The viewpoint character for that wild ride is, of course, Lucy (Scarlett Johansson), an American student in Taiwan whose relatively poor taste in men gets her literally handcuffed to an ominous-looking briefcase and told to deliver it to someone named “Mr. Jang.” Jang (Min-Sik Choi), it turns out, is quite the cold-blooded killer and druglord, and once Lucy makes her delivery he turns around and makes her the kind of offer that mobsters tend to love, the kind people tend not to refuse: be a drug mule and bring his new designer narcotic to markets abroad, or get yourself and everyone you ever cared about killed. Not a tough choice for the scared-out-of-her-wits Lucy.

But before her trip out of the country can even begin, an unforeseen bit of physical abuse leads to the drugs she’s carrying in her own body to leak and be absorbed directly into her bloodstream, initiating her metamorphosis into something only previously ever imagined: a human being utilizing more than just the 10% of the neural network in their brain that the average human theoretically uses. Thanks to her newly-expanded consciousness and cognitive abilities, Lucy is immediately aware of what’s happening to her body and to her mind, and thanks to some nifty new abilities she gains due to the mental boost she’s able to escape from Mr. Jang’s thugs with ridiculous ease. She then makes contact with Dr. Samuel Norman (Morgan Freeman), a researcher whose decades-long study of the human brain and its potential makes him the only person that can possibly understand Lucy’s transformation and the effects it might have.

As her mental capacity continues to increase and her abilities continue to evolve, Lucy races to meet Dr. Norman in Paris, enlisting the aid of a French cop (Amr Waked) as she’s being chased down by Mr. Jang and his cadre of dark-suited machine gun-toting hitmen. Like most everyone else, Jang doesn’t understand what’s happening to Lucy. H doesn’t care, either — he just wants his drugs back, and he wants to punish Lucy for her defiance by ripping them from her body in the most painful manner possible.

At first glance, the film has all the signature features of Besson’s most memorable action-thrillers. Drugs, guns, supervillain-like crime bosses to whom greed and cruelty comes as naturally as breathing, and a female character at the center of the action that finds a way to overcome her initial fears and turn the tables on the bad guys thanks to sheer force of will and a lot of ammunition, it’s all here, wrapped up in the slick and vibrant visual style that Besson has been perfecting over a film career spanning four decades. Fans of Besson’s previous film and TV work will recognize those trappings right away, and Lucy as a film will probably win their hearts on those merits alone.

But those stylistic and thematic motifs are just the starting point for Lucy. With his script, Besson has in mind to explore the most humanist of questions: just what are the limits of human consciousness and existence, what is its ultimate potential, and what price might be paid by an individual who might achieve that potential? Would such a person even be able to communicate with humans whose mental capacities are still held back by human limits? Would they even exist in space and time in the same way, perceive space and time the same way that ordinary humans do? And would other humans welcome the knowledge and awareness that such a being could provide, or would they fear and lash out at someone whose very perception of reality is beyond their comprehension? It’s heady, heady stuff, and to his credit Besson doesn’t try to water down or scale back his examination of these subjects in order to cater to audiences craving more blood, bullets, and adrenaline. He seeks a balance of action and speculation, and while the movie might get a bit talky at times, he more or less succeeds.

It certainly helps to have Scarlett Johansson out in front for a production like this. Johansson is and always has been a mesmerizing performer, and her recent action-oriented work in Marvel’s The Avengers and Captain America: The Winter Soldier has granted her instant credibility as someone who can convincingly carry a Besson-style actioner, and do it with charisma and verve. But her range as a dramatic performer serves her just as well here as her ability to saunter into an action sequence guns blazing. The role demands that she show an evolution not just of thought and awareness, but also of how emotion is perceived, processed, and emoted. Lucy’s connection to her own humanity is challenged in the course of the story, and it takes a special kind of acting talent to make that challenge believable and compelling to a movie audiences. Johansson has that kind of talent, and thus Lucy should stand as one of her most memorable films, as well as one of Besson’s.

As for the supporting cast, the standout here is easily Min-Sik Choi, who fans of Asian cinema should instantly recognize for his cult-favorite work in Oldboy and Lady Vengeance. Look closely at his manner and physicality, however, and you’ll see a great deal of Gary Oldman’s wild-eyed cop character in Leon: The Professional. It’s a fair imitation, and it’s done in homage, no doubt, but the inspiration is clear as day. Freeman, who gets second billing here, looks and sounds like he walked onto the Paris locations of the film fresh from his turn in Transcendence, his film from earlier this year in which he had to project scientific brilliance and occasionally spout some techno-babble. That’s not a knock on his work here — he does what he does very well. It’s just that it’s nothing we haven’t seen him do before.

Will everyone absolutely love it? Not likely. After all, it’s an action film that demands not only your attention, but your willingness to think and speculate, and in all fairness, that not what a lot of people go to any movie to do, much less action movies. But to those who do have a taste for films that get your brains going as well as your adrenaline, Lucy will be a treat for both the eyes and the mind.